1. 62 nd IETF – CAPWAP Working Group1 CAPWAP Objectives Saravanan Govindan March 2005

2. 62 nd IETF – CAPWAP Working Group2 Background WG draft –Combines objectives from individual submissions –Includes inputs from IETF 61 discussions Structure from CAPWAP charter –Prioritization of Objectives Mandatory & Accepted, Desirable, Rejected –Classification Architecture, Operations, Security, Operator requirements

3. 62 nd IETF – CAPWAP Working Group3 Architecture Objectives (1/2) Logical Groups (Mandatory) –Logical divisions of physical WTP –Protocol used to manage WLAN in terms of logical groups Support for Future Wireless Technologies (Desirable) –Protocol messages to be extensible for different layer 2 wireless technologies Support for New IEEE Extensions (Desirable) –Accommodate definitions by IEEE groups –e.g. APF AHC

4. 62 nd IETF – CAPWAP Working Group4 Architecture Objectives (2/2) Interoperability Objective –Local-MAC and split-MAC designs to work together –Protocol involves negotiations to determine appropriate split Interconnection Objective –Protocol operations to be independent of underlying transport technology Multiple Authentication Mechanisms (Desirable) –IEEE 802.11i support –Support for other mechanisms; e.g. web authentication

5. 62 nd IETF – CAPWAP Working Group5 Operational Objectives (1/3) Support for Traffic Separation (Mandatory) –User data and control traffic are mutually separated –Simplifies protocol operation Device Transparency (Mandatory) –CAPWAP protocol between AC and WTPs –Does not affect wireless terminals Configuration Consistency (Mandatory) –Regular exchange of WTP configuration information –e.g. WTP load, operational state Firmware Distribution

6. 62 nd IETF – CAPWAP Working Group6 Operational Objectives (2/3) System-wide Resource State (Mandatory) –Exchange of network state information – switching segment & wireless medium segment –e.g. congestion, interference levels Resource Control (Mandatory) –Protocol to maintain IEEE 802.11e QoS mapping across switching and wireless medium segments IEEE 802.11i Considerations –Authenticator and encryption points distinctly located –Key distribution among them (Mandatory)

7. 62 nd IETF – CAPWAP Working Group7 Operational Objectives (3/3) STA Admission Control –Access control needs to be based on both switching and wireless medium segments –e.g. control based on congestion and radio interference Trust Model Definition –Considerations for separation of authenticator and encryption locations Security Borderline Control (Desirable) –Mutual security between logical groups Centralized WTP Management (Rejected) –Protocol to be provisioned for WTPs not managed by AC

8. 62 nd IETF – CAPWAP Working Group8 Security Objectives CAPWAP Protocol Security (Mandatory) –Mutual authentication –Secure exchanges between AC and WTPs System-wide Security (Mandatory) –Prevention against outside threats –e.g. rouge wireless terminals & PMK sharing

9. 62 nd IETF – CAPWAP Working Group9 Discussions so far (1/3) Future Wireless Technologies –Protocol messages need to be extensible for other (non-IEEE 802.11) layer 2 technologies CAPWAP Protocol Security –“Key establishment protocol” to be secured against possible post-establishment compromises Transport Layer Independence –CAPWAP operations to be independent of IP versions –Protocol to operate over intermediate networks With possibly many hops Possibly under administrations

10. 62 nd IETF – CAPWAP Working Group10 Discussions so far (2/3) Interoperability Objective –Managing different split-MAC & local-MAC variations –Protocol can provide simple capabilities exchange AC can then decide if variations can/will be supported Traffic Separation –Control traffic not to be combined with data traffic Resource Control –QoS mapping for IEEE 802.11e and other IEEE TG semantics (TGk, TGu, TGv)

11. 62 nd IETF – CAPWAP Working Group11 Discussions so far (3/3) Statistics –Protocol to allow exchange of various statistics information; WTP load, loss rates etc. Device Transparency –Protocol to be transparent to wireless ‘devices’ instead of ‘users’

12. 62 nd IETF – CAPWAP Working Group12 Next Steps Discuss objectives further –Categorization Consider any additional objectives Finalize requirements and gain consensus

13. 62 nd IETF – CAPWAP Working Group13 Questions? Comments?